In end-to-end coupling of two optical fibers, the closer together the two fiber ends can be brought and aligned on their common center-line, the less light or power is lost. In connectors for such end-to-end coupling having ferrules to retain the optical fibers, the cleaved end of an optical fiber is initially just flush with the coupling surface of the ferrule. Thereafter, when the rear or cable-end portion of the ferrule is crimped to the jacket of the optical fiber cable, the cleaved end of the optical fiber may recede into the ferrule, and hence, back from the coupling surface thereof. Such a connector assembly is described in co-pending U.S. patent application Ser. No. 698,392, now U.S. Pat. No. 4,101,198, entitled "Fiber Optic Connector", filed June 21, 1976 by Earl R. Heldt, and assigned to the assignee hereof.
Co-pending U.S. patent application Ser. No. 792,375, now U.S. Pat. No. 4,114,979, entitled "Improved Fiber Optic Connector", filed Apr. 29, 1977 by Earl R. Heldt, also assigned to the assignee hereof, incorporates improvements which provide adjustment means for adjusting the position of the optical fiber end flush with the coupling surface of the ferrule during assembly. However, since the final step of assembly involves the crimping of an outer sleeve to the outer jacket of the cable, there is no means for readjusting the position of the optical fiber end with the coupling surface of the ferrule thereafter. Readjustment may be desirable (1) to improve production yield, since adjustment during initial assembly may be faulty or (2) to lengthen service life in the field, since the optical fiber may recede into the ferrule away from the coupling surface thereof with hard or extended use, or use in varying ambient temperatures and environments.